Move footer categories out of the application controller

Data are now loaded directly from layout. Maybe it is not the bast
solution, but it is better than having unnecessary instance variable in
all controller actions.
Extract Issue.find to method
Move root_path to IndexPages#show to be more RESTful
Save data to cookies only if they are valid
Rename show_modal to showModal
Change formatting
Extract adding fake values to own method
Change order of valides method calls
Move application wide partials to app/views/application
Create self.randoms method instead of using scope DSL
Change formatting in routes.rb
Design change on issue page
Fix description of some tests
Change order of factory definitions (alphabetically)